In the past, container blanks have been often formed by punching the blanks from sheet stock using, for example, a punch and die. While various methods were used to feed the sheet stock into the punch and die, accurate control of the length of feed was difficult and complicated. The difficulty of this problem was increased when the stock was printed so that the blanks had to be punched in registry with the printing.
This problem was sometimes overcome through the use of an auxiliary perforater on the printing press, which placed perforations on the feed stock in registry with the printing. The perforations were then used to register the printing on the stock. However, this system was complicated and required the use of special apparatus during the printing of the sheet stock as well as a compatable special apparatus to synchronize the container blanker to the perforations.
Alternatively, the prior art used complicated and costly crank arms, cams and followers to produce a feed system powered by the rest of the apparatus. This system exhibited problems in that the feed length could vary with machine speed. Also, it was difficult to change the feed length and precise registry was impossible.